It known to use composite electrodes in lithium batteries, wherein the composite electrode material comprises a complex oxide as the active material, a carbonaceous material as the electronic conducting and a binder.
U.S. Pat. No. 5,521,026 discloses a battery wherein the electrolyte is a solid polymer electrolyte, the anode is a lithium anode, and the cathode comprises a mixture of V2O5 and carbon black on a current collector. The composite cathode material is obtained by ball-milling the oxide and the carbon black in a liquid solvent, using stainless steel balls. Performances of such a battery are improved by ball-milling compared to a battery wherein the cathode components are simply mixed. However, using steel balls introduces impurities on the cathode material which leads to side reactions.
WO 2004/008560 describes a composite cathode material. Said cathode material is obtained by high energy milling a mixture of a non conducting or semiconducting material, a low crystallinity carbon (C1) and a high crystallinity carbon (C2). Carbon black is an example of low crystallinity carbon, and graphite is an example of high crystallinity carbon.
U.S. Pat. No. 6,855,273 describes a method for preparing an electrode material by heat treatment of a carbonaceous precursor in the presence of a complex oxide or the precursors thereof, in a controlled atmosphere. The electrode material thus obtained is made of complex oxide particles having a carbon coating and the conductivity thereof is substantially increased compared to the non coated oxide particles. The increased conductivity is due to the presence of the carbon coating which is chemically bonded to the oxide particle surface. The chemical bonds provide excellent adhesion and high local conductivity. The carbonaceous precursor may be a polymer precursor or a gaseous precursor. A composite electrode material is prepared by mixing the carbon coated particles with a carbon black, and PVDF as the binder. Carbon black must be added to the complex oxide particles when preparing the electrode to achieve a capacity of 170 mAh/g which is the theoretical capacity.
WO 2004/044289 discloses a composite material obtained by mixing vapor grown carbon fibers with a matrix material, said matrix material being a resin, a ceramic or a metal, to enhance thermal conductivity and electrical conductivity.
US 2003/0198588 discloses a battery wherein an electrode is made of a composite material comprising carbon fibers such as vapor grown carbon fibers. Carbon fibers exhibit a great intercalation property as a carbonaceous material for a negative electrode. A composite negative electrode material is prepared by kneading a mixture of carbon fibers and a binder.